19. Mount，本身表示加大，常用分词形式，延伸出来的增加、拓展、集聚等词都可以用 mount 来译。

国内经济下行压力持续加大
Downward pressure on China’s economy has continued to mount

新兴市场国家和发展中国家风险和挑战不断集聚
To the emerging markets and developing world in general, risks and challenges continue to mount

20. Era 本身是时代，汉译英时常用来翻译“新形势”、“新时期”、“新纪元”等词。

制定了新时期西藏工作的指导思想和特殊优惠政策
decided on guiding principles for the work in Tibet in the new era and issued favorable policies for Tibet’s development

新中国成立和阿拉伯国家相继独立，开创了中阿友好交往的新纪元。
The founding of the People’s Republic of China and the independence of Arab countries created a new era for China-Arab friendly exchanges.

21. Decide on，主要替换“制定”等词。

If you decide on something or decide upon something, you choose it from two or more possibilities.
作出决定

Denikin held a staff meeting to decide on the next strategic objective.
德尼金召开了员工大会为下一步的战略目标作出决定。